Gastro-esophageal implants

ABSTRACT

A satiation device is described which includes a sheath or liner extending from the proximal or middle stomach to the distal antrum. Food ingested by the patient passes through the sheath or liner, thereby minimizing contact between the ingested food and the stomach. It is believed that over time, reduced contact between food and the stomach will result in decreased Ghrelin production by the patient and a consequent decrease in appetite. In some embodiments, the satiation device may also include a proximal pouch and/or a distal bypass tube.

This application is a continuation of U.S. application Ser. No.10/345,914, filed Jan. 16, 2003, which is a continuation-in-part of U.S.application Ser. No. 09/940,110, filed Aug. 27, 2001 and U.S.application Ser. No. 10/118,289 filed Apr. 8, 2002, which claims thebenefit of U.S. Provisional Application, No. 60/379,306, filed May 10,2002.

FIELD OF THE INVENTION

The present invention relates generally to the field of devices andmethods for achieving weight loss in humans, and specifically to the useof devices implantable within the human stomach for controlling feelingsof hunger and/or limiting food intake.

BACKGROUND OF THE INVENTION

Various medical approaches are used for controlling obesity. Theseapproaches include diet, medication, and surgical procedures. One of themore successful surgical procedures is the vertical gastroplexy orproximal gastric pouch procedure in which a portion of the proximalstomach is formed into a small pouch with a small opening into theremainder of the stomach. This proximal gastric pouch may include aRoux-en-Y anastomosis in which a portion of the jejunum is connected tothe pouch so as to shunt food from the proximal region of the stomachinto the intestine, thereby minimizing absorption of food into thebloodstream. However, known complications are present with each of theseprocedures and more successful options are desired.

Other alternatives include implantation of gastric balloons that preventovereating by occupying volume within the stomach. Unfortunately,gastric balloons can migrate down the GI tract, causing obstruction andthus necessitating removal.

It is therefore desirable to provide a successful and minimally-invasivealternative to existing approaches for controlling obesity.

SUMMARY OF THE INVENTION

A satiation device utilizing principles of the present inventionincludes a sheath or liner positioned within the stomach. Food ingestedby the patient passes through the sheath or liner, thereby minimizingcontact between the ingested food and the stomach. It is believed thatover time, reduced contact between food and the stomach will result indecreased Ghrelin production by the patient and a consequent decrease inappetite. In some embodiments, the satiation device may also include aproximal pouch and/or a distal bypass tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a human stomach and a portion ofthe small intestine.

FIG. 2A is a side elevation view of a first embodiment of a satiationdevice.

FIG. 2B is a side elevation view of the pouch and chute of theembodiment of FIG. 2A.

FIG. 3 is a schematic illustration of a human stomach illustrating invivo positioning of the embodiment of FIG. 2A.

FIG. 4 is a schematic illustration of a human stomach illustrating invivo positioning of a second embodiment of a satiation device.

FIG. 5 is a schematic illustration of a human stomach showing in vivopositioning of an exclusion liner

FIG. 6 is a schematic illustration similar to FIG. 5 showing anexclusion liner having a distal tube.

FIG. 7 is a schematic illustration similar to FIG. 5 showing anexclusion liner having a proximal pouch.

FIG. 8 is a schematic illustration similar to FIG. 5 showing anexclusion liner having a proximal end at the middle stomach/proximalantrum.

FIG. 9 is a schematic illustration of a human stomach and proximal smallintestine showing positioning of a bypass tube extending from theproximal stomach into the small intestine.

FIG. 10A is a cross-sectional side elevation view showing one example ofa mechanism for attaching the pouch and the tube of FIG. 9.

FIG. 10B is a cross-sectional side elevation view showing a secondexample of a mechanism for attaching the pouch and the tube of FIG. 9.

FIG. 11 is a schematic illustration of a pylorus showing a tetherconnecting proximal and distal portions of the tube of FIG. 9 andextending past the ampulla vader.

DETAILED DESCRIPTION

An anatomical view of a human stomach S and associated features is shownin FIG. 1. The esophagus E delivers food from the mouth to the stomachS. The z-line or gastro-esophageal junction Z is the irregularly-shapedborder between the thin tissue of the esophagus and the thicker tissueof the stomach wall. The gastro-esophageal junction region G is theregion encompassing the distal portion of the esophagus E, the z-line,and the proximal portion of the stomach S.

Stomach S includes a fundus F at its proximal end and an antrum A at itsdistal end. Antrum A feeds into the pylorus P which attaches to theduodenum D, the proximal region of the small intestine. Within thepylorus P is a sphincter that prevents backflow of food from theduodenum D into the stomach. The middle region of the small intestine,positioned distally of the duodenum D, is the jejunum J.

Ghrelin is a satiety hormone secreted by cells in the stomach and thesmall intestine. Increased production of Ghrelin, such as before a meal,causes a person to experience hunger. After the person has eaten,production of Ghrelin decreases. It is presently believed that 85% ofthe Ghrelin-secreting cells are found in the stomach, and that theremaining 15% are in the antrum and small intestine. Obese patients havebeen found to possess significantly higher Ghrelin levels than non-obesepatients. Moreover, recent studies have found that a patient'sproduction of Ghrelin decreases significantly following gastric bypassprocedures such as the Roux-en-y procedure described above. Variousversions of the embodiments described herein provide an exclusion sleeveor liner situated within the stomach and extending from the proximal ormiddle stomach to the distal stomach or the small intestine. Over time,the presence of the exclusion sleeve will cause the Ghrelin-secretingcells to decrease Ghrelin production, causing the level of hungerexperienced by a patient to decrease and thus resulting in weight lossby the patient.

Some of the embodiments of exclusion sleeves also include a pouch orfunnel positioned at the gastro-esophageal junction region so as to forma small reservoir which collects masticated food from the esophagus. Thepouch may limit the amount of food that can be consumed at one time.Additionally or alternatively, as the pouch fills with food, it maydistend, imparting pressure against the upper stomach and loweresophageal sphincter causing the patient to experience sensations offullness. Over time the food within this reservoir descends into theexclusion sleeve through a distal opening in the pouch. The pouch mayoptionally include a proximal tubular extension positionable within theesophagus to facilitate flow of food from the esophagus into the pouch.Various pouches of a type suitable for use with the exclusion sleeve aredescribed in U.S. application Ser. No. 10/118,289, filed Apr. 8, 2002,which is hereby incorporated by reference for all purposes.

The devices may be modular in that where multiple components (e.g. asleeve and pouch) are to be implanted, the various components may beprovided separately from one another. In such a modular system, theseparately implanted components may be attached to one another withinthe body during implantation, or certain ones of them may remainunattached to one another even after implantation. Alternatively, thephysician may assemble the components to one another just prior toimplantation. Modular components are desirable in that they permit thephysician to select sizes for each component that are appropriate forthe patient.

Implantation of the described devices is preferably performedendoscopically, by passing the devices through the esophagus, preferablyunder endoscopic visualization. Alternatively, the devices may beimplanted using surgical or laparoscopic procedures.

One embodiment of a satiation device is illustrated in FIG. 2A andincludes a pouch 12 positioned within an elongate exclusion sleeve 14.For the purposes of this application, the term “satiation devices” willbe used to mean devices intended to induce weight loss in one or more ofa variety of ways. These include, but are not limited to, physicallyrestricting the amount of food that can be consumed, and/or impartingpressure against portions of the body (e.g. stomach, esophagus,esophageal sphincter, etc) causing the patient to experience sensationsof fullness, and/or affecting levels of hormones or other substances inthe body that control or affect feelings of hunger, and/or affecting theamount of ingested food absorbed by the body.

Pouch 12, shown without the sleeve in FIG. 2B, includes a funnel-shapedproximal portion 16 with an opening 18 that is positionable at thegastro-esophageal junction region (and preferably below the z-line) asshown in FIG. 3. Although a funnel shape is preferred here, a variety ofalternative shapes may be used for the proximal portion of the pouch.For example, the pouch may have a much shorter proximal-to-distaldimension and thus take the shape of a shallow saucer with a small holeon its bottom surface. Other examples include, but are not limited to,egg shapes, other tapered shapes such as the shape of a “spinning top”,cylindrical shapes, and other symmetrical or asymmetrical shapes.

Because of its small volume (which may be on the order of approximately2 cc-300 cc in volume, but is preferably in the range of 10-30 cc), thepouch functions to limit the amount of food that can be consumed at onetime. Over time the food within this reservoir descends into theexclusion sleeve 14 through a distal opening in the pouch.

A distal chute 20 extends from the funnel-shaped proximal portion 16 andincludes a distal opening 22. In this embodiment, the chute 20 tapersoutwardly from the funnel 16 to form a valve 24 between the funnel andchute. The valve 24 may be formed of an elastic material that permitsthe valve opening to increase in size to permit large pieces of food topass through. If desired, he diameter of the valve 24 may be adjustableby endoscopic means, such as by tightening a ligature around the valve,inflating an inflatable cuff positioned around the valve, or usingvarious other means. This increases the effectiveness of the pouch bydecreasing the exit diameter—thereby causing food to exit the pouch moreslowly and prolonging the feeling of fullness experienced by thepatient. Likewise, the diameter of the valve 24 may be endoscopicallyincreased by deflating a fluid filled restrictive cuff, using a tool tocut or stretch open the valve, or using various other means, to increasethe ability of the patient to tolerate the pouch by permitting morerapid emptying of the pouch.

Pouch 12 may be formed of a flexible material that will prevent passageof food through the sides of the pouch. Examples of such materialsinclude, but are not limited to polyesters (e.g. Dacron.®. polyester),ePTFE fabric (e.g. GoreTex.®. fabric or others), a polyurethane such asChronoFlex.®. polyurethane, nylon fabrics, silicone, other polymericmaterials, and bio-absorbable materials (e.g. PLLA, PGA, PCL,poly-amhydride etc). The pouch may be formed of a composite ofcompliant, semi-compliant and/or non-compliant materials which givedifferent regions of the pouch different degrees of compliance so as toallow/limit expansion of the pouch in various locations. For example, itmay be desirable to provide the pouch with a fairly elastic exit port toas to prevent occlusion in the event a large piece of food is ingestedand/or to control the exit pressure of food from the pouch, whereas theproximal end of the pouch may be stiffer to prevent bulging. Varyingdegrees of compliance may also be built into the pouch by varying thecross-sectional thickness in different regions of the pouch. Thematerial may be coated with a lubricious, bio-compatible, chemicallyinert material, such as paraleyne, to reduce friction on the basematerial's surface which will help prevent sticking and food build up onthe device.

Sleeve 14 is a flexible tube having a proximal opening 23 and a distalopening 26. The sleeve material may be similar to the material describedwith respect to the pouch 12, but should be sufficiently flexible topermit peristalsis. The exterior of the sleeve material may beimpregnated with substances known to inhibit release of Ghrelin or otherhormones associated with feelings of satiety. Such substances may bechemical or pharmaceutical substances, therapeutic molecules or cells,or genetic material. The sleeve may also be impregnated with an acid toinhibit production of Gastrin, or its exterior may be impregnated withan anti-Gastrin antibody.

The sleeve 14 and pouch 12 are preferably attached to one another attheir respective proximal openings 18, 23 using sutures, clips,adhesives or other suitable means. These components may be attached toone another during manufacture or just prior to implantation, or theymay be separately implanted.

The proximal portion of the sleeve 14 contains a plurality of openings28 sized to allow gastric secretions to enter the sleeve 14 to aid indigesting food that has passed from the pouch 12 into the sleeve 14 andto allow drainage of the secretions from the stomach. The stomachsecretions exit the stomach via the sleeve and drain into the pylorus.The openings 28 may take the form of perforations or slots in the sleevewall. Alternatively, the openings may take the form of apertures in meshor porous regions in a portion of the sleeve. For example, ePTFE with anopen cell structure is a material that can be constructed to allowgastric secretions to enter without allowing food to exit.

In the embodiment shown in FIG. 3, the openings are positioned such thatwhen the pouch 12 is positioned within the sleeve 14 for use, the distalopening 22 of the chute 20 is preferably distal to the openings 28 so asto prevent food from exiting the sleeve through the openings 28. Theopenings 28 may be positioned in any other locations as well,particularly if the openings are small enough to prevent food frompassing through. Examples of alternative locations for the openingsinclude locations near the distal end of the sleeve (see FIG. 4), orlocations substantially along the entire sleeve length.

The diameter of the sleeve 14 is sufficiently large to allow the pouchto be enclosed within the sleeve 14, but is preferably sufficientlynarrow to permit acids produced within the stomach to flow into contactwith the walls of the antrum. It is believed that such contact is neededfor normal regulation of the hormone Gastrin. Gastrin is a physiologicalregulator of gastric acid secretion within the stomach. IncreasedGastrin levels result in increased secretion of gastric acids. Acidlevels that are too high can produce ulcers.

Secretion of Gastrin (and thus resultant secretion of gastric acids) isinhibited when cells in the antrum detect a low pH. It is thus importantfor acids in the stomach to contact the antrum to ensure normalregulation of Gastrin. If the acids are not permitted to contact theantrum, Gastrin production would increase, and might thus cause anincreased production of gastric acids that could lead to stomach ulcers.

Methods for implanting satiation devices such as pouch 12 are shown anddescribed in U.S. application Ser. No. 10/118,289 filed Apr. 8, 2002.For example, some of the disclosed methods involve packaging thesatiation device within a deployment tube, inserting the distal end ofthe tube into the stomach (preferably from the esophagus), ejecting thesatiation device from the tube using a pushrod passed through tube, andthen securing the satiation device using sutures, clips, adhesives,radial forces, stents or stent-like structures, etc. Such methods may beutilized to deploy the satiation devices described herein, including thepouch 12 and sleeve 14.

During implantation the pouch 12 is secured at the gastro-esophagealjunction region G using sutures, clips, adhesives, stents or stent-likestructures, or other suitable means. One suture attachment device founduseful for applying sutures between the pouch and tissue is the“Sew-Right” suturing device available from LSI Solutions of Victor, N.Y.

Although the pouch may be secured to the esophageal tissue, it is morepreferable to apply sutures/clips below the Z-line to allow forattachment to the thicker tissue of the stomach wall. Suture attachmentpoints, which may take the form of holes, anchor loops, eyelets,windows, or grommets 30 in the pouch may be used to provide regions(which may be reinforced) for anchoring the sutures. Although as few oras many of such suture/clip attachment points as needed may be used, atleast four such points are desirable, such as at 90.degree. intervalsaround the pouch, so as to enable the pouch to be secured around thefull circumference of the tissue. The suture attachment points may bemade of a suitably dense radio-opaque material, such as titanium orgold, to add in visualization of the device during or after theprocedure. Each suture attachment point may also be marked using adifferent color to facilitate identification and orientation of sutures.If the pouch is formed of a less durable material, the proximal portionof the pouch (in which the eyelets 30 are located) may be formed of moredurable material such as a woven material, Dacron.®. polyester or ePTFEfabric so as to provide a more secure sewing region. Although loops,grommets, eyelets or reinforced regions may be advantageous, the pouchmay alternatively be provided without suture attachment points formed ofspecial materials (with or without identifying markings)—in which casethe sutures are passed directly through the pouch material.

The flexible pouch and/or sleeve material may be reinforced with,constructed of, or supported by supporting members, such as a soft mesh,a cage structure, ribs, rings etc. The supporting members may be formedof stainless steel, polymer, shape memory materials such as nitinol,shape memory alloys, or shape memory polymers, or thickened regions ofmaterial. The pouch and/or sleeve may be constructed so as to beself-expanding, such that the pouch and/or sleeve springs radially openinto an expanded condition upon ejection from a deployment device orcatheter as described above.

The proximal end of sleeve 14, near proximal opening 23, may be attachedto the pouch 12 alone, or it may be attached to the pouch 12 and to thesurrounding tissue. The sleeve 14 is attached at its distal opening tothe distal stomach (e.g. at the antrum) near the pylorus, so as to allowfood exiting the sleeve 14 to flow out of the stomach to the smallintestine. Attachment is made using sutures, clips, adhesives, stents orstent-like structures or other suitable means.

FIG. 4 shows an alternative embodiment of a satiation device 10 a usinga pouch 12 a and sleeve 14 a. The satiation device 10 a differs fromthat of FIG. 3 primarily in that the pouch 12 a is provided without adistal chute (see chute 20 FIG. 3), and in that the openings 28 a in thesleeve are positioned at the distal end of the sleeve so as to permitdrainage of gastric secretions into the sleeve 28 a and from the sleeveinto the pylorus. Drainage of gastric secretions is desirable to avoidaccumulation of such secretions in the stomach.

The sleeve 14 a (and also the sleeve 14 of FIG. 3) may besemi-impermeable, allowing gastric secretions to enter without allowingfood to exit. Materials such as ePTFE with open-cell structure (e.g.node to fibril lengths of 20-100 micron) are suitable for this purpose.

The embodiments of FIGS. 3 and 4 are believed to cause weight loss in anumber of ways. First, as the pouch fills with food, it may distend,imparting pressure against the upper stomach and lower esophagealsphincter causing the patient to experience sensations of fullness afterconsuming small quantities of food. Second, it is believed thatisolating consumed food from the walls of the stomach using theexclusion sleeve 14, 14 a will lead to a temporary increase in thepatient's production of Ghrelin followed by a “burn out” phenomenon overtime in which the Ghrelin is reduced, in turn leading to decreasedsensations of hunger. Third, digestion is delayed and absorption of thefood is minimized.

FIGS. 5 through 8 show additional embodiments that also control satietyby isolating consumed food from the walls of the stomach so as toeventually decrease day-to-day production of Ghrelin by the patient dueto the above described “burn out” phenomenon. Each of these embodimentsincludes an exclusion liner that is positioned within the stomach suchthat consumed food passes through the liner and then exits the liner toflow into the small intestine via the pylorus.

Referring to FIG. 5, a first exclusion liner 32 includes a proximalopening 34 positioned in the proximal stomach, such as at thegastro-esophageal junction region G, and a distal opening 36 positionedin the antrum A, preferably adjacent to the pylorus P. The liner 32 maybe proportioned to substantially line the stomach while still allowingclearance for gastric acids (labeled H+ in FIG. 5) to contact the wallsof the antrum surrounding the liner—so as to prevent overproduction ofGastrin as described above. Alternatively, the liner may have asignificantly narrower diameter if desired. As shown in FIG. 5, liner 32reduces contact between ingested food and the stomach, including thefundus and the antrum.

The proximal region adjacent to the proximal opening 34 is preferablysecured to tissue at the gastro-esophageal junction region below the Zline using sutures, clips, adhesives, stents or stent-like structures orother suitable means. The distal region adjacent to the distal openingmay be secured in a leak-proof manner to the distal antrum, or it may besecured more loosely to permit gastric secretions to exit the stomachinto the pylorus (see arrows in FIG. 5). For example, clips or sutures,etc. may be applied in a manner that leaves a gap between the distalopening 36 and the pylorus to permit drainage of gastric secretions.Alternatively, if such drainage is desired, the liner 32 may be providedwith a plurality of openings (see, for example, openings 28 a in FIG. 4)that allow gastric secretions to flow into the liner and then into thepylorus. As another alternative, liner may be supported by a cagestructure having resilient cage members that contact the walls of thestomach to prevent migration of the liner within the stomach, but thatallow clearance between the stomach walls and the exterior of the liner.Cage structures of a type that may be adapted for this purpose are shownand described in U.S. application Ser. No. 09/940,110, filed Aug. 27,2001, the entirety of which is incorporated by reference.

FIG. 6 shows an exclusion liner 32 a that is similar to the liner 32 ofFIG. 5), but that further includes a distal tube 38 that is secured inthe pylorus or duodenum using sutures, anchors, clips, stents orstent-like structures, adhesives, etc. Again, this distal connection maybe leak proof to prevent drainage of secretions, or it may configured toallow such drainage.

FIG. 7 shows an exclusion liner 32 b that is similar to the liner ofFIG. 5, except that it includes a proximal pouch 40 attachable at thegastro-esophageal junction region. As with the embodiment of FIGS. 3 and4, the pouch 40 fills with food when the patient eats, causing thepatient to experience sensations of fullness after consuming smallquantities of food. The pouch 40 may be integral with the liner 32 b, orit may be separately attachable prior to or during implantation. As withthe embodiments of FIG. 5 and FIG. 6, the distal end of the liner 32 bmay be attached to the distal antrum in a manner that permits drainageof secretions present outside the liner, or in a manner that occludessuch drainage. The embodiment of FIG. 7 may also be provided with adistal tube similar to the distal tube 38 of the FIG. 6 embodiment.

FIG. 8 shows an antral exclusion liner 32 c proportioned to extend fromthe middle stomach or the proximal antrum to the distal antrum. Liner 32c includes a large proximal opening 42 and a smaller distal opening 44as shown. The proximal region of the liner 32 c is secured to thesurrounding walls of the stomach, and the distal region is secured tothe distal antrum. Liner 32 c may be secured in a manner that permitsflow of some food and stomach secretions around the liner 32 c asindicated by arrows in FIG. 8, or it may be secured tightly against thestomach walls such that all food and stomach secretions are directedthrough the liner 32 c. The embodiment of FIG. 8 may be provided with adistal tube similar to the tube 38 of FIG. 6.

Materials that may be used for the liners of FIGS. 5-8 include flexiblematerials that will prevent passage of food through the sides of thepouch. The materials may be fluid impermeable or slightly permeable.Slightly permeable materials (e.g. ePTFE with open-cell structure on theorder of 20-100 micron node to fibril length) may be desirable in thatthey allow gastric secretions to pass into the liner without allowingfood to exit.

Examples of materials useful for the liner include, but are not limitedto polyesters (e.g. Dacron.®. polyester), ePTFE fabric (e.g. GoreTex.®.fabric or others), a polyurethane such as ChronoFlex.®. polyurethane,nylon fabrics, silicone, other polymeric materials, and bio-absorbablematerials (e.g. PLLA, PGA, PCL, poly-amhydride etc). The liners may beformed of a composite of compliant, semi-compliant and/or non-compliantmaterials which give different regions of the sleeve/pouch differentdegrees of compliance so as to allow/limit expansion of the sleeve/pouchin various locations. For example, it may be desirable to provide theliner with a fairly elastic exit port to as to prevent occlusion in theevent a large piece of food is ingested. The material may be coated witha lubricious, bio-compatible, chemically inert material, such asparaleyne, to reduce friction on the base.

The exterior of the liner material may be impregnated with substancesknown to inhibit release of Ghrelin or other hormones associated withfeelings of satiety. Such substances may be chemical or pharmaceuticalsubstances, therapeutic molecules or cells, or genetic material. Theliner may also be impregnated with an acid to inhibit production ofGastrin, or its exterior may be impregnated with an anti-Gastrinantibody, or any of a variety of therapeutic drugs or molecules.

The liner may be reinforced with, constructed of, or supported by asupporting structure, such as a soft mesh, coil, a cage structure, ribs,rings etc. The supporting structure may be formed of stainless steel,polymer, shape memory materials (such as nitinol, shape memory alloys,or shape memory polymers), bio-absorbable materials or, in the case of asilicone liner, thickened regions of silicone. The supporting structuremay be located at the interior or exterior of the liner material. It maybe molded into or sewn to the liner material, or it may be attachedusing a suitable adhesive. If a tightly woven mesh or tightly wound coilis provided, the flexible material may be eliminated. Alternatively, amesh may be provided having a polymeric material embedded in theinterstices of the mesh, in which case a separate internal or externalcovering of liner material may be eliminated. The polymer may beimpregnated with an agent that will decrease Ghrelin secretion orneutralize stomach acidity.

The inner diameter of the liner (and/or supporting structure) may becoated with lubricious material such as Teflon or parylene to ease thepassage of food through the liner.

The liner is preferably constructed so as to be self-expanding, suchthat the pouch springs radially open into an expanded condition uponejection from a deployment device or catheter. In one example of amethod of deploying a liner such as the liners of FIGS. 5-8, the linermay be compressed and inserted into a deployment tube. In this example,the distal end of the deployment tube is inserted (preferably throughthe esophagus) into the stomach and the liner ejected from the tubeusing a pushrod passed through tube. The liner expands within thestomach, and the physician secures the liner to the stomach usingsutures, clips, adhesives, stents or stent-like structures, radialforces, etc.

FIG. 9 illustrates an alternate satiation device that includes anelongate bypass tube 46 that is implanted to extend from the proximalstomach, through the pylorus and into the small intestine (for example,through the first 24 inches of the small intestine). As with priorembodiment, tube 46 reduces the amount of contact between ingested foodand the stomach and thus may eventually result in decreased Ghrelinproduction. It also functions similar to a Roux-en-y bypass in that itreduces the amount of surface of the small intestine that is availablefor absorbing food. The tube is preferably made of a thin-walled polymerthat is flexible enough to allow peristalsis within the small intestine.It also bypasses the bile and pancreatic ducts, which insert digestiveenzymes into the small intestine.

It may be desirable to position the tube so that it does not contact theampulla of vader (an opening in the duodenum through which bile passesinto the duodenum) so as to minimize the chance of irritation andcholeocystitus. For example, a narrow tether 50 (FIG. 11) may connectthe proximal portion 52 a of the tube (which is disposed proximal of theampulla vader) to the distal portion 52 b of the tube so as to avoidobstructing the ampulla. Distal portion 52 b may include a funnel-shapedproximal end to facilitate re-entry of food into the tube 46 after thefood has passed the ampulla vader.

Lastly, referring again to FIG. 9, tube 46 may be provided with aproximal pouch 48, similar to the pouch of FIG. 3, that may distend whenfilled with ingested food, imparting pressure against the upper stomachand lower esophageal sphincter causing the patient to experiencesensations of fullness. The pouch 48 and tube 46 may be separatelyimplantable and then attached to one another in situ.

FIGS. 10A and 10B show two examples of configurations for attaching thepouch 48 and tube 46. In one configuration, the proximal end of the tube48 may be inserted into the distal opening of the pouch 46 as shown inFIG. 10A. In another, the distal end of the pouch 46 may be insertedinto the proximal end of the tube 48 as shown in FIG. 10B. Naturally,other means of attachment may be used, including sutures, hooks, stentsor stent-like structures and/or adhesives.

Various embodiments of satiation devices have been described herein.These embodiments are given by way of example and are not intended tolimit the scope of the present invention. It should be appreciated,moreover, that the various features of the embodiments that have beendescribed may be combined in various ways to produce numerous additionalembodiments. Moreover, while various materials, dimensions, shapes,implantation locations, etc. have been described for use with disclosedembodiments, others besides those disclosed may be utilized withoutexceeding the scope of the invention.

1. (canceled)
 2. (canceled)
 3. A gastro-esophageal implant comprising: acylindrical component configured for attachment to a gastro-esophagealjunction region of a patient, wherein a proximal end of the componentincludes a plurality of attachment points for anchoring the component totissue of the gastro-esophageal junction region, the attachment pointsincluding holes; and a sleeve attached to the component and extendingdistal to the component, the sleeve comprising a side wall that includesa plurality of openings to permit passage of a material therethrough,the plurality of openings being distal to the attachment points of thecomponent; wherein, upon implantation, the implant forms a conduit fordirecting food from an esophagus through the implant directly to anintestine of the patient.
 4. The implant of claim 3, further comprisinga plurality of attachment elements, wherein the component is configuredto be anchored to the tissue via the attachment elements passing throughrespective holes of the plurality of attachment points.
 5. The implantof claim 3, wherein the plurality of attachment points includes at leastfour attachment points.
 6. The implant of claim 3, wherein the pluralityof attachment points are spaced evenly about the proximal end of thecomponent.
 7. The implant of claim 3, wherein a proximal end of thesleeve is attached to the component only, such that, upon implantation,the proximal end of the sleeve is not attached to tissue of the patient.8. The implant of claim 3, wherein the component and the sleeve areconcentric.
 9. The implant of claim 3, wherein the plurality of openingsof the sleeve comprises at least a first opening and a second openingdistal to the first opening.
 10. The implant of claim 9, wherein thefirst opening and the second opening are arranged in a row and alignedin a proximal to distal direction.
 11. The implant of claim 3, wherein,upon implantation, a distal end of the sleeve is positioned proximate apylorus of the patient.
 12. The implant of claim 3, wherein theplurality of attachment points comprise a radiopaque material.
 13. Theimplant of claim 3, wherein at least a portion of the sleeve issemi-permeable.
 14. A gastro-esophageal implant comprising: acylindrical component configured for attachment to a gastro-esophagealjunction region of a patient, wherein a proximal end of the componentincludes a plurality of attachment points for anchoring the component totissue of the gastro-esophageal junction region; and a sleeve attachedto the component and extending distal to the component, the sleevecomprising a side wall that includes a plurality of openings comprisinga first opening and a second opening, wherein the first opening isdistal to the attachment points of the component, and the second openingis distal to the first opening; wherein, upon implantation, the implantforms a conduit for directing food from an esophagus through the implantdirectly to an intestine of the patient.
 15. The implant of claim 14,wherein the first opening and the second opening are arranged in a rowand aligned in a proximal to distal direction.
 16. The implant of claim14, wherein the plurality of attachment points includes holes spacedevenly about the proximal end of the component, the plurality ofattachment points being configured to anchor the component to tissueproximate a Z-line of the gastro-esophageal junction region.
 17. Theimplant of claim 16, further comprising a plurality of attachmentelements configured to anchor the component the tissue by passingthrough respective holes of the plurality of attachment points.
 18. Theimplant of claim 14, wherein the sleeve comprises a polymer, the sleevebeing sufficiently flexible to permit peristalsis of the intestine uponimplantation.
 19. A method for positioning a gastro-esophageal implantin a patient, the method comprising: anchoring a cylindrical componentof the implant to a gastro-esophageal junction region of the patient viaa plurality of attachment points at a proximal end of the component, theplurality of attachment points including holes, wherein the component isattached to a sleeve extending distal to the component; and positioninga distal portion of the sleeve proximate a pylorus of the patient, thesleeve comprising a side wall that includes a plurality of openingsdistal to the attachment points of the component, wherein the pluralityof openings permit passage of a material therethrough; wherein theimplant forms a conduit for directing food from an esophagus through theimplant directly to an intestine of the patient.
 20. The method of claim19, wherein anchoring the component to the gastro-esophageal junctionregion comprises passing a plurality of attachment elements throughrespective holes of the plurality of attachment points.
 21. The methodof claim 19, wherein the plurality of openings of the sleeve comprisesat least a first opening and a second opening distal to the firstopening.
 22. The method of claim 21, wherein the first opening and thesecond opening are arranged in a row and aligned in a proximal to distaldirection.